I would like the Story 'create subtask' menu pick to actually default to creating a sub-task

[scott.lake]

use case:

Story type issue is present on screen.

Click the 'more' tab and select 'create sub task'.

Jira defaults to creating a board task rather than a sub-task.  Why is that?  Shouldn't the 'create sub task' menu pick actually default to creating a sub-task?

Perhaps it's my rather newbie use of Jira and my understanding of what a sub-task is:  a task that is subordinate to a task, a list item that must be completed before the task itself can be considered completed.  Is that an incorrect understanding of what a sub-task is in Jira-World?